Added wrapper for the xmlURIPtr type, provided accessors, fixed the

* python/generator.py python/libxml.c python/libxml2-python-api.xml
  python/libxml2class.txt python/libxml_wrap.h python/types.c:
  Added wrapper for the xmlURIPtr type, provided accessors, fixed
  the accessor generator for strings
* python/tests/Makefile.am python/tests/tstURI.py: added a specific
  regression test.
Daniel

python/tests/tstURI.py

@@ -0,0 +1,41 @@
+#!/usr/bin/python -u
+import sys
+import libxml2
+
+# Memory debug specific
+libxml2.debugMemory(1)
+
+uri = libxml2.parseURI("http://example.org:8088/foo/bar?query=simple#fragid")
+if uri.scheme() != 'http':
+    print "Error parsing URI: wrong scheme"
+    sys.exit(1)
+if uri.server() != 'example.org':
+    print "Error parsing URI: wrong server"
+    sys.exit(1)
+if uri.port() != 8088:
+    print "Error parsing URI: wrong port"
+    sys.exit(1)
+if uri.path() != '/foo/bar':
+    print "Error parsing URI: wrong path"
+    sys.exit(1)
+if uri.query() != 'query=simple':
+    print "Error parsing URI: wrong query"
+    sys.exit(1)
+if uri.fragment() != 'fragid':
+    print "Error parsing URI: wrong query"
+    sys.exit(1)
+uri.setScheme("https")
+uri.setPort(223)
+uri.setFragment(None)
+result=uri.saveUri()
+if result != "https://example.org:223/foo/bar?query=simple":
+    print "Error modifying or saving the URI"
+uri = None
+
+# Memory debug specific
+libxml2.cleanupParser()
+if libxml2.debugMemory(1) == 0:
+    print "OK"
+else:
+    print "Memory leak %d bytes" % (libxml2.debugMemory(1))
+    libxml2.dumpMemory()